Automatic book exchange



A g- 1930- A. R. WOMRATH AUTOMATIC BOOK EXCHANGE- Original Filed June 15, 1925' 3 Sheets-Sheet 2 ATTORNEY Aug. 5, 1930.

A. R. WOMRATH 1,772,408

AUTOMATIC 1206K EXCHANGE Original Filed June 13,1923 5 Sheets- Sheet s a I, W

' ATTORNEY '2 a coin COIltfOl mechanism associated With the Figs, 5 and 6 are transverse sectionalviews 75 Patented Aug. 5, 1930 i i I STATES i PATENT OFFi CE I nnrnun n. WQMRATH, or sournronr, CONNECTICUT i v AUTOMATIC; noon'nxonniven Application filed June 13, 1923, Serial No. 645,099. Renewed December 15.19%.

This invention relates to an exchange de- The invention accordingly comprisesthe vice, and aims to provide an apparatus of this features of construction, combination of ele-v character which may beutilized in connec ments, 'andarrangement of parts, which will tion with dispensing and exchanging of artibe exemplified in the constructions herein- 5 cles, such as for example books. after set forth and the scope of the applica- A further object of this invention is that of tion of which will be indicated in the claims. providing an automatic exchange device by For a fuller understanding of the nature means of which a systemof exchange may and objects of the invention, reference should be practiced in that an article may be depositbe had to the following detailed description 19 ed within said device and another article taken inconn-ection. with the accompanying withdrawn from the same upon certainmechdrawings, which i anisms being operated, thisactuation of the Fig. 1 is a partly sectional front elevation parts'being accomplished entirely by the user of an exchange device, certain of the exterior of the device without any assistance from an parts'of which have been broken away to dis- 15 attendant. I clos'e'the underlyingconstruction;

A still further object of this invention 1s Fig. Qis aside elevation'thereof; that of constructing a device of the nature Fig. 3 is a front View of a portion of the stated, in which it will be incumbent upon mechanisinforming apart of said device; the person using the same to depositan arti- V Fig. 3 is a similar view showing the parts v cle Within the apparatus before gaining a0- in a position different fromthat shownin cess to another ofthe same. i Fig. 3; a

Another object of this invention is thatof Fig. 4: is a further view similar to Fig. 3 furnishing anexchangedevice in the nature but showing the parts instill difi'erent relaof a vending machine, which Wlll incorporate tion to each other;

device in such a manner as to prevent a withtaken along the lines 5-5 and 6-6 respecdrawalof any of the articlesreposing therein, tively, and in the direction of the arrows inunlessa coin of prop er denomination hasbeen dicated in Fig. l;

deposited within said mechanism. Fig. 7 is an end view of a portion of the 30 Still another object of this invention is mechanism shown inFigs. 1 and 3 so that of providing a device of the nature Fig. 8 is a perspective view of the type of stated, in which a structure will be inCOrpoarticle which maybe vended by the exchange rated preventing any actuation of the appadevice; ratus and consequential exchange of articles Fig. 9 is a partly sectional frontview of 'a in the event of a user of the same depositing'a form of device different from that illustrated spurious article therein' in Figs. 1 to 7 An additional object is that of constructing Fig? 10 is a sectional plan view taken along vanexchange device incorporating mechanism thelines 10-10 of Fig. 9'; by means of which a locking of the device.

Fig. 11 isa' sectional plan'view taken along 40 maybe prevented until the desired articles is the lines 11 -11 ofFig. 9; and

finally withdrawn, so that it will bepossible Fig. 12 is a diagrammatic view oftheesfor the user of the device to withdraw andinsential parts of the" apparatus as shown in dividually examine any desired number of Figs. 9 toll, and indicating the circuit em the articles and tofinally. reach a decision-as ployedin this form of mechanism.

/ to which of the same he desires, Without re- In the illustrated embodiments of the in- 9 peatedly depositing additionalcoins to, per vention, the apparatus has been shownas a mit of thisbeing done. 7 device for use in connection with a book Other objects of the invention will in part exchanging. system, such as may be employed be obvious and: will in part appearhereim in a rental library. While the invention has after." v beendesigned particularly for this purpose,

it is here to be understood that the same is readily applicable for use in numerous other associations wherein the dispensing and exchanging of articles is to be eflected.

Thus, referring more particularly to Figs. 1 to 7, it will be seen that the reference numeral 1 indicates a casing of any suit-able size anddesign which may be formed'of any desirable material. Partitions extend transversely of this casing and provide compartments 3, 4 and 5, access to which is normally prevented by means of closures such as panels 6, 7 and 8 associated, one with each of the compartments aforementioned.

lVith a view of supporting and permitting a proper actuation of these closures, and to provide an article-locking mechanism a shaft 9 may be rotatably mounted beyond the compartments in bearing members 10 andll. A longitudinal movement of the shaft is prevented in any desirable manner, such as for example by securing collars 12 and 13, at points adjacent its ends, which collars engage the bearing members and counteract any tendency of axial movement. The panels are connected with the shaft 9 by attaching the same, one to each of the hubs 14, which latter rotatably encircle the said shaft and are each provided with a slot 15 within which a pin 16 extends, this pin being attached to the shaft and being held in engagement with the rear wall of the slot byany suitable means, such as a spring 11, which has one of its ends secured to the bearing member 11, its opposite end being attached to the collar 13; the purpose of this construction being hereinafter brought out.

Interposed bet-ween each pair of hubs 14 are looking dogs 17 which are mounted for longitudinal movement with respect to the casing 1, but are prevented from rotating with the'shaft 9 by any desirable means, such as for example by a lug 17 attached one to each of the dogs and slidably engaging a fixed track 17 Formed in one of the edges of each of the dogs and hub members are two pairs of recesses or notches 19 and 20, the second pair being of a depth less than the depth of the pair first mentioned. Formed on the opposite edges of each of the dog and hub members are projections act ing as cams, which are shaped to correspond to the recesses 19 and are adapted to extend into the same. Thus it will be seen that when the parts are in the position shown in Fig. 1, the collars and hub members will form one continuous sleeve, encircling the major portion of the shaft 9, but when one of the closure members is swung so as to render one of the compartments accessible, all of the collars and hub members to the right of the one which supports the closure in question will be moved longitudinally of the shaft 9 to a distance equal to twice the depth of one of the recesses 19. This actuation of the parts is to be attributed to the fact that incident to the rotation of the hub member and the recesses formed therein as well as the cams 18 carried thereby, that this member will be caused to ride outwardly along the shaft, and this outward motion will be continued until the apex of the cams carried by the hub bear against the fiat edge portion of one of the next adjacent dogs 17, while the cams of the dog located adjacent the opposite edge of the hub similarly engage the fiat rear edge thereof. A continued swinging of the closure will result in the cams carried by the'hub member and the dog last mentioned, finally reaching a position at which they will ride into the notches or recesses 20 formed respectively in the dog first mentioned and the said hub members, and the parts will then be in the position shown in Fig. 4, the purpose of this disposition of the mechanism being later brought out. An intimate engagement of the hub members and collars one with another is at all times assured by preferably utilizing a compression spring such as 21, which encircles the shaft 9 and has one of its ends bearing against the collar 13, while its opposite end engages a dog disposed beyond the outermost hub. Thus the tension of this spring or the spring 11 may be accurately adjusted by moving the collar 13 either longitudinally or rotatively with respect to the shaft.

To normally prevent a movement of the closure members, a latch 22 is employed, which latch is positioned adjacent one of the ends of the shaft 9 and has its head shaped to provide a series ofshoulders 25, 26 and 28,and this latch is caused by means of a spring 23 to bear against a lug 27, carried by the outermost dog 17. A disengagement of these parts may be effected, however, in that the'body of the latch constitutes an armature with which a solenoid24 cooperates, and their release may thus be accomplished by energizing this latter member.

Carried at the outer end of the shaft is a commutator 34, presenting contact segments 43, 44 and 45, which are adapted to be engaged by fingers 35,36, 37 and 38. To furnish a token lock control, a member providing a slot 42 is positioned at a point convenient to the casing 1, and disposed within the slot is a contact member 40, which, when a token or coin is deposited, is adapted to engage, and in cooperation ,with a lever 41, to

retain the same against further movement.

The lever above mentioned has one of its ends extending into the coin slot, its opposite end being pivotally mounted as at 47, and an armature 48 is attached to this lever and is adapted 'to cooperate with a solenoid 39,

which latter has one lead connected with the contact finger 35, its second lead being connected with one of the terminals of a battery A. Pairs of spaced contacts 30 and 31 are connected in series and disposed within each .Liil) of the compartments, and the solenoid 24 is connected with thel contact 30 in the compartment 5, and a lead extends from the contact 31 in compartment 3 to the contact finger 37 The secondarylead of the solenoid 24 is connected with the battery A and the lever 41 is'connected in series with the battery and solenoid 24, etc while a further lead extends from the battery and is connected with the contact finger 38, and it will be noted that the insulated contact member 40 has a lead connected with it, which lead has its opposite end attached to the finger 36.

The invention viewed in certain aspects embraces a mechanism which is electrically actuated and where the same is employed for the practicing ofa system of book exchange, it will be seen, reference being had to Fig. 8, that the article embraces a book. In the present embodiment of the invention there is secured to this book a contact member in the nature ofa bridging portion 32, this member being of suh'icient length to close the circuit between the spaced contacts 30 and 31, against which it is pressed by springs 33 associated with each compartment. Due to articles within the apparatus for a spurious article, and it will be appreciated in this connection that the member 32 may be of any desired shape and the contacts or actuating portions with which this member cooperates may be correspondingly disposed'within each of the compartments to insure against a fraudulent operation of the device. Thus an article lock control is provided, in that an article will be subject to deposit ineach compartment before the circuit may be completed through the mechanism.

In use, it is to be'understood in the type of machine which has been afore-described, that one of the compartments has its closure swung to the position indicated in dotted lines in Fig. 2, this com'partment being the one from which the last article has been withdrawn. The closure of this compartment being in the position aforementioned, the mechanism controlling the operation of all the closures will be in the position shown in Fig. 4, and in this position of the parts it willbe obvious thatthe opening of a second closure is prevented; first due to the fact thatthe shoulder 26of thelatch willengage the lug 27; secondly, for the reason that one of the closures is open, the parts will be incapable ofmoving to a suflicient extent longitudinal of the shaft to permit of the opening of a second of the closures, and thirdly, incident to the fact that when one of the closure members isopen the, contact segment 45 will engage the fingers 35 and 36, so that no circuit can be completed whichwill cause an iii) dotted lines in Fig. l, at which point thexcircuit will be closed through the battery A, solenoid 24, contacts30, bridging portions 32, contacts 31, finger 37, segment 44, finger 36, contact member 40, the coin, lever 41, and so back to the battery A thus energizing the solenoid 24. This closing of the circuit, preferably is prevented from occurring due to the disposition of the fingers 36 and 37 and segment 43, until the closure member which is to be swung to its open position has been slightly moved'to bring the lug 27 into engagement with the shoulder 25 of the latch to thus guard against waste of current. Upon the solenoid 24 being active, the latch 22 will be elevated against the tension of the spring 23, and the closure may be swung to a partially open position, at which point the circuit will be closed through the battery A,

solenoid 24, contacts 30, bridging portions 32, contacts 31, finger37, segment 44, finger 38, and so back to the battery A. Thus, the latch is continued in elevated position so that the lug 27 may clear theshoulder 26 of the same, and finally when thislug has reached a position adjacent the shoulder 28 of the said latch, it will be understood that the cam members carried bythe hub 14 to which the closure is attached will ride into the shallow notches 20 formed in the edge of the adjacent dog, while the corresponding shallow notches formed in the opposite edge of the hub will be'engaged by t-hecam members associated with the oppositedog. Upon the closure reaching this fully open position, it will be understood that the space between the fingers 35 and 36 will be bridged'by the segment 45, and thusthe circuit in thisinstancewill be closed through the battery A,

solenoid 39, the fingers and segment aforementioned, the contact member 40, the coin, the lever 41, and so back to the battery. Thus the solenoid 39 will be energized andthis will result in an immediate attraction of the armature 48, causing the lever 41 to be swung to a point at which thecoin is freeyto drop down the slot 42 into a suitable receptacle.

The article within the compartment which is now open may be withdrawn, and it will be seen that-the parts will remain in the posi tion first described in connection with the operation of the device, and'the entire operation will be repeated when a second article is to be exchanged; r

If desired, mechanism may be provided permitting of an operator withdrawing and examining an article without causing the parts to assumetheir locked position, this being accomplished by the use of a lever 49, which is pivotally mounted adjacent the coin slot, and has its inner end capable of being swung to a point (indicated in dotted lines in Fig. 1) at which it will prevent the coin from descending through the slot regardless of the movements of the lever 41. Thus, if an operator is uncertain as to whether he desires an article but wishes to examine the same, he may simply deposit a coin within the slot to effect an operation of the parts in the manner aforementioned, andby swinging the lever 49 against the tension of the spring 50, the coin will be held in such position that he may individually examine each one of the articles. It is to be noted, however, that according to the present embodiment of the invention it will be absolutely necessary to return each article to a compartment and to close the same before it is possible to open a second of these compartments, for the reasons afore-described.

Finally, it will be understood in connection with the apparatus aforementioned, that the same may be enclosed within a casing 51, which will form a continuation of the casing 1, and tangentially disposed slots 52 may be provided in the first mentioned casing to accommodate the movements of the arms which connect each of the closure panels with their respective hub members. In this connection, the purpose of the spring 11, slots 15 and pins 16 is apparent, in that due to the provision of these parts each of the hub members is capable of turningindependently of others of the same, and the turning of any hub member will effect a corresponding movement on the part of the shaft 9. Thus, a device is presented which will be extremely rugged and simple in construction, and positive in operation, and which will prevent any attempt of fraudulent operation of the mechanism on the part of the user, it being further understood that although for the purpose of illustration I have shown the device as being controlled electrically, that the same may readily be constructed in such a manner as to be capable of mechanical operation. 7

Finally referring to the structure shown in Figs. 9 to 12, it will be seen that in these figures there is illustrated a slightly different form of exchange device than has been shown in the figures before described, it being noted that in these latter views there is shown a device in the nature of a revolving book-case. It will be seen that the receptacle in these views includes a body 105, which is formed with a suitable series of radially extending compartments 107. Encircling the body 105 is a casing 103, formed with an opening 104,

of sufficient size to permit of the withdrawal of one of the articles from its compartment, and the body 105 is rotatable with respect to the casing 103 by mounting the former on a shaft 106. Afiixed to the shaft is an annular plate formed with a series of notches 109, corresponding in number to the number of compartments 107 provided in the body of the device.

With a view of normally preventing movement of the body of the receptacle with respect to the casing thereof, it will be seen that a latch 110 is provided, which is pivotally mounted as at 111, the end of this latch being bent as at 112 to form a portion adapted to individually engage the notches 109, and in order to disengage these parts a solenoid 113 is mounted above the body of the latch, it being thus seen that upon the solenoid being energized the latch will act as an armature, and a consequent disengagement of the same from the plate 108 will be effected. A coin slot 115 is positioned adjacent to the apparatus aforementioned, and disposed within this slot is an insulated contact member 117. P0- sitioned adjacent to the contact member, and also extending into the slot, is one arm of a lever 118, which is pivotally mounted as at 119, the opposite end of this lever carrying a pin 120. Secured to the latch as at 122, and beyond the pivot 111 of the same, is a block 121, formed with a bevel surface which normally engages the pin 120 by virtue of a spring 124 provided for this purpose, it being noted that a stop member 123 is utilized to limit the movement of the block with respect to the latch.

In use, an article such as that shown in Fig. 8 is exchanged by thrusting the same into that compartment 107, which is in registry with the opening 104 of the casing, and the bridging portion 32 of this article serves to close the circuit through the contacts 130 and 131, which are provided in pairs within each of the compartments. Now upon a token or coin of proper denomination being deposited within the coin slot 115, the circuit will be closed throughv the battery 13, contact memher, 117, coin, lever 118, solenoid 113, contact 131, portion 32, contact 130 and so back to the battery. This closing the circuit will result in an energization of the solenoid, and a consequent attraction of the armature provided by the latch, and this action will result in the latch being lifted to permit of a rotation of the receptacle body 105 to a point at which that article which is to be withdrawn is in registry with the opening 104. It will be noted that as a consequence of the elevation of the latch, the block 121 will rock with respect to the latch body, and slide past the pin 120. Upon the article aforementioned being withdrawn, the circuit will be broken between the contacts 130 and 131, which will cause a stoppage of the flow of current through the windings of the solenoid, and a consequent return of the latch to its normal position-i. e., in engagement with-one of the notches of the plate. Simultaneously with this relockingof apparatus, the upper face of the block 121 will engage pin 120 to rock the lever 118, and thus permit of the release of the coin so that the latter may fall into the" receptacle llt'provided for this purpose. Similarly to the apparatus described in connection with Figs. 1 to 7, an operator may individually examine each one of the articles in that the lever 133, which is pivoted adjacent the coin slot 115, as at 134;, may be swung to. a point at which it will prevent the coin from dropping into the receptacle 116, and thus the operator is free to examine each one of the articles to be vended, it being noted, however, that each of these articles. is .returnable before a second of the same may be rendered available, due'to the fact that the circuitis broken upon the withdrawal of each of the articles. However, upon the operator leavingthe apparatus, the lever 136 will swing to its normal position by Virtue of the action of the spring 135, and the coin will drop, thus finally breaking the circuit and requiring the depositing of a new coin, in orderto again effect an exchange of articles.

Summarizing the operation somewhat, it may be observed,-taking the construction in Fig. 1, for example, that when the'exchange apparatus isready for operation,'one ofv the closures, or book retainers, 6 7, or 8, is open. To operate the apparatus the patron has a token and a book suitable for exercisingcontrol. The'book may beobtained froman attendant, or may already be in possession of the operator. One of the most important features requires that the service shall be paid for and that abook'shall be returnedto the apparatus in exchange for the book to be removed from the apparatus. Thus the token pays for the service,andbook is exchanged for book.

' The apparatus provides 'forexchange of books in a practical manner; it is a library and contains many books, either of which may 7 i be exchanged for the patrons book. As far as possible equal values of books are exchanged for one token. Having placed the patrons book in-tlie empty compartment andthe token in the opening 42, the particular closure may be moved to closed position and any other one closure may then be moved to open'position, in the exchange operation of the device. Un-' less the control effect of the token control deviceis made variable by operation of the lever 49, only one book retainer may be low ered for one token. This variablecontrol may be omitted if desired. But even-if not used it will bie'noted that after deposit of token and book,"any book maybe selected and removed. It will benoted that the token in con junction with the parts controlled thereby provides a retainer control device which is operable independently of the control keys of the book, although in the present embodiment bothare required intorder that exchange operation may be effected.

The invention accordingly comprises the features of construction,combinations ofelements, and arrangement. of parts, which :will be exemplified in the constructions herein after set forth and the scope of the application of which will 'beindicated in the claims. it is also to-be understood that the following claims .are intended to cover all of. the generic andzspecific features of the invention herein described, and all statements of the scope .of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention what I claim as new and desire to secure by Letters Patentis;

1. A device for practicing a system of book exchange including in. combination means for normally retaining a pluralityof books against removal from said device and means forming a part of a further book'and acting to release said first named means to permit of a withdrawal of any of saidfirst named books. Q

2. A vending device including in combination means for normally retaining ,a plurality of key-carrying books against removal :thereofkey-carrying books against removal there from and means operated by associatingan' additional key-carrying book with said def vice, to permit of the removal of only'oneof said first named books'therefrom. i

5.. .An exchangedevice including in combination aplui'ality' of receptacles, means associated with each ofsaid receptacles whereby thesame may be retained in a-=closed-condi tio'n"; each of said receptacles being adapted to contain an article and means carried by said articles to cooperate with said receptacleclosing means, whereby upon an articlebeing deposited within one of said receptaclesianother of the same may be opened,"

,6. An article exchange apparatus in which aplurality of articles are adapted to'be locked I againstexchange including, in combination,

atoken lockcontrol device and anarticlelock controldeviceand means requiring the-actuationof both of'said control devices to unlock the apparatus forexohange.

7. An article exchange apparatus in which a plurality of articles are adapted to be locked against exchange including, in combination, a token lock control device and an article lock-control device, means requiring the actuation of both of said control devices to unlock the apparatus for exchange, and means whereby an exchange of articles relocks the apparatus against exchange.

8. An article exchange apparatus in which a plurality of articles are adapted to be locked against exchange including, in combination, a token lock control device and an article lock control device, means requiring the actuation of both of said control devices to unlock the apparatus for exchange and means for proportioning the number of articles received relative to the number of articles delivered in a single exchange actuation of the apparatus.

I 9. An article exchange apparatus in which a plurality of articles are adapted to be locked against exchange including, in combination,

.'a token lock control device and an article lock control device, means requiring the actuation of both of said control devices to unapparatus and means adapted to be operated by exchange actuation of the apparatus to permit the delivery of any article.

10. An article exchange apparatus in which a plurality of articles are adapted to be locked against exchange including, combination, atoken lock control devlce and an article lock control device, means requiring the actuation of both of said control devices to unlockthe apparatus for exchange,means for proportioning the number of articles delivered in 'a single exchange actuation of the apparatus, means adapted to be operated by exchange actuation of the apparatus to permlt the delivery of any article'and means adapted to be set to permit a pluralityof exchanges of articles for unlocking actuation of the exchange apparatus. I r

' 11. An article exchange apparatus in Which "a plurality of articles are adapted to be locked against exchange including, in combination, a token lock control device and an article-lock control device, means requiring the actuation of both of said control devices to unlock the apparatus for exchange, means for proportioning. the number of articles received relativeto the number of articles delivered in a single exchange actuation of the apparatus and means whereby an exchange of articles ,relocks the apparatus againstfurther exchange.

: 12. An articleexchange apparatus in which article lock control device, means requiring the actuation of bothof said control devices .to unlock the apparatus for exchange, means whereby anaexchange of articles relocks the apparatus against a further exchange and means adapted to be operated by exchange actuation of the apparatus to permit the delivery of any article.

13. An article exchange apparatus in which a plurality of articles are adapted to be locked against exchange including, in combination, a token lock control device and an article lock control device, means requiring the actuation of both of said control devices to unlock the apparatus for exchange, means for proportioning the number of articles received relative to the number of articles delivered in a single exchange actuation of the apparatus and means adapted to be set to permit a plurality of exchange of articles for unlocking actuation of the exchange apparatus.

14. An article exchange apparatus in which a plurality of articles are adapted to be locked against exchange including, in combination, a token-lock control device and an article lock control device, means requiring the actuation of both of said control devices to unlock the apparatus for exchange, means for proportioning the number of articles received relative to the number of articles delivered in a single exchange actuation of the apparatus, means whereby an exchange of articles relocks the apparatus against further exchange, means adapted to be set to permit the delivery of any article and means adapted also tobe set to permit a plurality of exchanges of articles for unlocking actuation of the exchange apparatus.

15. .An article exchange apparatus in which a plurality of articles are adapted to be locked against exchange including, incomhination, atoken lock control device and an article lock control device and means whereby an exchange of articles relocks the apparatus against further exchange.-

16. An article exchange apparatus in which a plurality of articles are adapted to be locked against exchange including,in combination, a token lock control device and an article lock control device, means for proportioning thenumber of articles received relative to the number of articles delivered in a single exchange actuation of the apparatus, means whereby an exchange of articles relocks the apparatus against further exchange and means adapted to be operated by exchange actuation of the apparatus to permit the d'elivery of any article.

17. An articleexchange apparatus in which a plurality of articles are adapted to be locked against exchange including, in combination, a token lock control device and an article lock control device, means for proportioning the number of articles received relative to the number of articles delivered in a single ex-' change actuation of the apparatus, means whereby an exchange of articles relocks the apparatus against furtherexchange, means adapted to be operated'by exchange actuation of the apparatus to permit the-delivery of any article and means adapted to be set to permit a plurality of exchanges of articles for unlocking actuation of the exchange apparatus.

18. An article exchange apparatus in which aplurality of articles are adapted to be locked against exchange including, in combination, unlocking mean, and means whereby an on change of articles relocks the apparatus against exchange. i j a 19. An article exchange apparatus in which a plurality of articles are adapted to belocked against exchange including, in combination, unlocking means,and means whereby an exchange of articles relocks the apparatus against exchange, the unlocking operation of said apparatus being effected only by articles of a predetermined character.

20. An article dispensing device includ ing, in combination, means providing an electric circuit embracing. a plurality of separate pairs of terminals, article retaining means controlled through said circuit and adapted to be actuated to permitthe removal of a predetermined number of saidarticles less than all of the same and means actuated in response to the removal of articles to operatively set sai'd retaining means againstthe removal of additional articles. l

21. An article dispensing device including, in combination, means providing an electric circuit embracing a plurality of separate pairs of terminals, article retaining. means controlled through said circuit adapted to permit an actuation of said retaining means for the removal of a predetermined number of said articles less than all'of the same,

means actuated in responseto said removal of articles to operatively set said retaining a means against the removal of additional articles and circuit controlling m'eans'including an artiole to be dispensed, said article being adapted to be positioned inthe device to completethe circuit at one pair of said terminals.

- 22. An article dispensing device including, in co1nbination,means providing an electric circuit ,embraciug a plurality oil-separate airs of terminals, article retainingmeans controlled throu h said circuit adapted to; be

pair of said terminals and means including a token-for completing the circuit atanother pair of said terminals.

' 23. In a library, in combination, means adapted to lock a plurality or books against exchange, a token lock control, a book lock control, means rcquirinthe action of both of said controls to unlock the books for ex change andineans adapted to restrict the number of exchanges to the number of tokens deposited in the receiver therefor.

24. A vending device, including in combination, a receptacle adapted to contain articles, a closure for said receptacle, a coin controlled means for locking said closure in closed position, andmeans controlled by the .presence of an article in said receptacle for retaining said closure in operable condition. 25. A vending device, including means providing a plurality of compartments adapted to contain articles, a closure member for each of said compartments, a shaft adjacent said compartments, hub members secured to said shaft, a locking dog cooperating with said hub members for normally preven'aing movement of the same, and means cooperating with said dog whereby the same may be moved to permit of an opening ofany of said closures.

' 26. A vending device, including means providing a plurality of compartments adapted to contain articles, a closure mem her for each of said compartments, a shaft adjacent said compartments, hub members secured to saidshaft, a locking dog cooperating with said hub members for normally preventing movement of the same, a lug forming a part of said dog, a latch normally engagingsaid lug, and means for throwing said latch to permitof an opening of any of "said closures.

- 27; A vending device, including a casing providing a series of compartments, ashaft adjacent said casing, a closure for eachof said compartments, hub members encircling said shaft and attached one to each of said closures, locking dogs disposed adjacent tov said hubmembers, cams forming a part of saiddogs andmembers, said dogs andhub members being also formed with notches adapted to cooperate with'said cams, means acting to cause a constant engagement of said a members and :dogs, a lug forming apart of one ofsaid elements, a latch engagingfisaid lug, and means for throwing? said latch whereby said lugjmay be moved and said closures may be opened.

28. A vending'device including a'casing',

formed with a series of compartments. pairs of contact membens disposed one within each 7 v partment,'means for controlling opening of any of saidclosures including an armature, a

solenoid positioned'adjacent said armature and connected with said contact members,

said solenoid being adapted to also be con nected with a source of electrical energ ,and means for closing a circuit through said source of energy, solenoid and contact me1nbers, whereby to actuate said armature.

29. A book exchange apparatus adapted to contain. a plurality of books including, in combination, means adapted to lock the apparatus against exchange of books and requiring cooperation of a token and a control book to unlock the apparatus for exchange of a control book unlocks the apparatus for rality of books.

exchange of either of the other books for the control book and compels retention of the control book in the apparatus for the exchanged book, and means adapted to be so set that the presence of the token inthe apparatus and the addition of the control book to the apparatus is adapted to unlock the apparatus for successive exchanges for said token.

31. A book exchange apparatus adapted to contain a predetermined plurality of books including, in combination, means adapted to lock the apparatus against exchange of books, and means for unlocking the apparatus for exchange of books including unlocking control devices dependent, for unlocking actuation to permit exchange, on the presence in said apparatus of said predetermined plu- 32. A book exchange apparatus adapted to contain a predetermined plurality of books including, in combination, means adapted to lock the apparatus against exchange of books, and means for unlocking the apparatus for exchange of books including unlocking con- I trol devices dependent, for unlocking actuation to permit exchange, on the presence in said apparatus of said predetermined plu r ality of books, said control devices including a token controlled device.

' article exchange apparatus including, in combinatiommeans for normally retaining each of a plurality of control carrying articles in the apparatus adapted tobe actuated to permit the removal of one of said articles, acontrol carrying article adapted to be received in said apparatus, a token lockcontrol device, and means adapted, on

deposit of a control carrying, article in said apparatus and a token in said token lock control device, to release said retaining means so as to permit removal 'of another of said articles from said apparatus.

34. An exchange device including a receptacle adapted to contain an article, and means adapted to control opening and closing of said-receptacle including a device associated with the contained article to control opening of said receptacle. 35. A library for exchange of books including, in combination, a control key provided on each of a plurality of said books, and means requiring the presence of a. plurality of said key-provided books in the library in order to exchange a key-provided book for another book.

36. A library for exchange of books including, in combination, book retainer means, a control key provided on each of a plurality of said books, and means requiring the presence of a plurality of said key-provided books in the library in order to permit operation of said retainer means to effect exchange of books. I

37. A library for exchange of books in cluding, in combination, book retainer means, a control key provided on each of a plurality of said books, means requiring the presence of a plurality of said key-provided books in the library in order to permit operation of said retainer means to effect exchange of books, and a retainer means control device, operable independently of said keys, adapted to cooperate with said keys in order that exchange operation may be effected.

38. A library for exchange. of books including, in combination, a book retainer means, a control key provided on each of a plurality of said books, means requiring the presence of a plurality of said key-provided books in the library in order to permit operation of said retainer means to effect exchange of books a retainer means control device, operable independently of said keys, adapted to cooperate with said keys in order that exchange operation may be effected, and means for varying the control effect of said -independently operable device.

39. A book exchange library of the character described and having electrical control means limiting exchange to book for book, each bookcarrying an exchange-controlling, electrical contact member.

In testimony whereof I aiiix my signature.

ARTHUR R. WOMRATH. 

